[sk]% time cut -d, -f"1-15" numbers.csv > out.csv 5.670u 0.340s 0:06.27 95.8% [sk]% time perl -lanF, -e 'print join ",", @F[0..14];' numbers.csv > o +ut.csv 31.950u 0.200s 0:32.26 99.6%